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Comment: Re:rpi comparison (Score 1) 41

by mirix (#49427925) Attached to: Armstrap Claims to Make ARM Prototyping Easier (Video)

They're also awesome. Think of them like the AVR or PIC with more.. everything. More RAM. More ROM. More IO. More interfaces, both type and quantity. More Hz. Same price, they work with GCC.

I've been getting STM32s from china for cheaper than the basic AVRs on an arduino (not sure how, as even qty 1000 is like 4x the price on digikey, but they work like the real thing, so who knows?!).

I used to love AVRs, but whenever I go back to them now, they seem so limited. the ARM MCUs have a bit of a learning curve, but it's so worth it. With GCC and libopencm3, it's an entirely open source setup. The nucleo boards are dirt cheap arduino-ish things, to get started on, with integrated programmer & debugger.

There's really no reason to use 8bit MCUs anymore, unless you're making a $0.40 gadget, and need to squeeze out that last nickel.

Comment: Re:USB was no longer standard either (Score 1) 392

by mirix (#49231121) Attached to: Does USB Type C Herald the End of Apple's Proprietary Connectors?

Price. Why spend $4 where $0.05 will do, and will likely never fail anyway? It's a last ditch protection system, not really something that should be tripping all the time.

That said, it used to be fairly common to have breakers on a couple circuits (headlights, for one).

In addition to cost, I'd suppose reliability might be a second consideration. Breakers have contacts in them, which with enough vibration and temperature/humidity cycling might fail, I guess... whereas a fuse has none.

What else.. fuses are faster, better current breaking capacity for DC (at least at this price point). I'd guess the tempco might be better too. (the trip point both devices moves with ambient temperature).

Comment: Re:So... (Score 2) 107

by mirix (#49230873) Attached to: Lawsuit Claims Major Automakers Have Failed To Guard Against Hackers

That's how it generally works already. Important stuff is on one CAN bus (ECU, ABS pump, auto trans controller if it has auto trans, airbags, etc). All the secondary stuff like door modules (controls locks, windows, etc), cabin illumination, the radio/navi and whatnot are on a secondary CAN bus (or LIN, or..).

This way if your rear door module dies and manages to take down the (secondary) bus, the car still runs.

I don't see much point in securing it, as you need physical access anyway. I'd rather see it go the other direction, standard, open interface, instead of each manufacturer using a proprietary communication scheme. (CAN only defines lower layers).

This is like suing computer makers for people being able to hack a computer they have physical access to. It's not possible to prevent.

Comment: Re:Alternate Bank of Canada Press Release (Score 1) 223

by mirix (#49186335) Attached to: <em>Star Trek</em> Fans Told To Stop "Spocking" Canadian $5 Bill

Here's the rules, FWIW. Pennies are only valid to 25c.

(2) A payment in coins referred to in subsection (1) is a legal tender for no more than the following amounts for the following denominations of coins:

        (a) forty dollars if the denomination is two dollars or greater but does not exceed ten dollars;

        (b) twenty-five dollars if the denomination is one dollar;

        (c) ten dollars if the denomination is ten cents or greater but less than one dollar;

        (d) five dollars if the denomination is five cents; and

        (e) twenty-five cents if the denomination is one cent.

Comment: Re: Star Wars! (Score 4, Interesting) 253

by mirix (#49162621) Attached to: 20-Year-Old Military Weather Satellite Explodes In Orbit

These ran NiCd cells. Here's some TL;DR from NASA about a variant of NiCd they use(d), not sure if it applies here.

http://www.nasa.gov/offices/oc...

Short notes:
Fancy NiCd, Higher density and sealed. They rely on precise chemistry to be hermetically sealed units (lean on one element, for limiting and only O2 production).
High pressure at full charge (~60PSI at room temp), higher if things go south, Pressure drops with charge state.
Excess discharge causes hydrogen production.

So, tin can, pressure changing with charge cycles (metal fatigue over many cycles?), H2 production, O2 production... maybe there is some chance for catastrophic failure there.

We don't know one millionth of one percent about anything.

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